Study On Parameter Extraction Methods Of Gan-Based Device Models

GaN material is the representative of the third generation of wide-bandgap semiconductor material.It has the advantages of strong irradiation resistance,high saturated electron velocity,thermal stability,high electron transport density and high power density.The heterojunction formed by GaN and its alloy materials has a strong polarization electric field and forms two-dimensional electronic gas with high electron mobility.These unique advantages make GaN devices widely used in the field of high-power and high-frequency microwave devices.In this paper,the models of GaN-based electronic devices and the extraction methods of its model parameters are studied respectively.The model parameters extraction methods proposed in this paper is universal and provides new methods for extracting model parameters of other electronic devices.1.The Angelov DC FET model is improved.The improved model can more accurately describe the output characteristics of AlGaN/GaN HEMTs with global variation of output current with gate voltage and drain voltage under the same group of model parameters.The same genetic algorithm is used to extract the parameters of the improved model,the average relative errors are 4.58%and 1.80%,respectively which shows that the improved model can describe the output characteristics of AlGaN/GaN HEMTs more accurately.Thus,an accurate global DC model is provided for AlGaN/GaN HEMTs,this model and method are universal.2.A new absolute error function used to extract the parameters of HEMTs nonlinear model is proposed,by which it can be to avoid calculation errors and significantly reduce the inaccuracy of parameter extraction.In this paper,we used three error functions to extract the parameters of AlGaN/GaN HEMT device model.The comparison results show that the absolute error function proposed in this paper is more accurate and effective.Therefore,it provides an effective and accurate method for the parameter extraction of electronic device model in the future.3.Due to the anisotropic properties of material of GaN and InN,which resulting in different crystal to mobility is different,this paper investigate along the c-axis??-A direction?and along the basal plane??-M direction?growth of the material.The Farahmand Modified Caughey Thomas?FMCT?model is often used to describe describe Negative differential mobility of nitrides,because there is no parameters of FMCT model along??-A direction?and??-M direction?.This paper develop a weighted error function.The error function and genetic algorithm was applied to extract the model parameters of two direction.This method can be extended to extract the parameters of FMCT model of other III-V nitride materials and their alloys.In order to apply the anisotropy of GaN and InN to NDR devices for device manufacturing.The Silvaco-Atlas platform was used to carry out two-dimensional numerical simulation in this paper,and the characteristics of GaN and InN Gunn diodes were simulated in detail,including the FMCT mobility model and parameters extracted in this paper were applied to the simulation process.Through the comparing the simulation results of GaN and InN Gunn diode in the two direction,the results show that along??-A direction?than??-M direction?obtain higher frequency and conversion efficiency.This provides a reference for design and manufacture of GaN and InN Gunn diodes.4.In the design and application of Schottky barrier diode,accurate current model is essential.Therefore,it is very important to determine the model parameters of Schottky barrier diode,such as Schottky barrier height,ideal factor n and series resistance Rs.A thermal emission model considering the the effect of voltage on the barrier was proposed by D.donoval et al.However,it can not be solved by traditional methods because the thermal emission model is a self consistent equation.For the above reasons,this paper proposes a new method for extracting the parameters of thermal emission model based on genetic algorithm,which provides a new method for extracting the parameters of schottky barrier diode model.5.Improving the breakdown voltage of schottky barrier diode is of important role for its application as a high-voltage device.This paper studies the breakdown characteristics of AlGaN/GaN.Firstly,the influence of field plate structure on the breakdown characteristics of AlGaN/GaN Schottky barrier diode?SBD?is studied.In addition,the breakdown voltage of AlGaN/GaN SBD is also related to the dielectric material under the field plate.Thus,the passivation layer dielectric material is studied.On the basis of the same structure of the field plate,five kinds of high?material,Si₃N₄,Al₂O₃,HfO₂,La₂O₃ and TiO₂,were used as passivation layers.It was found that the breakdown voltage of AlGaN/GaN SBD increased with the increase of dielectric constant of high?materials.Therefore,we can get two ways to improve the breakdown voltage,using field plate structure and high?dielectric materials.Based on the study of field plate structure,the reverse breakdown voltage of AlGaN/GaN SBD can reach 1350V by using step field plate structure and TiO₂ high?dielectric materials as passivation layer.6.In this paper,AlGaN/GaN/AlGaN/GaN SBD and AlGaN/GaN/InGaN/GaN schottky diodes are studied.The effect variation Al component and the thickness of AlGaN layer and GaN layer on the AlGaN/GaN/GaN SBD are investigated.The variation of the aluminum and indium components effect on the of AlGaN/GaN/InGaN/GaN SBD are studied.The thickness of AlGaN layer and InGaN layer effect on the AlGaN/GaN/InGaN/GaN SBD are also studied.Thus,it provides reference for designing and fabricating the double channel Schottky barrier diode.